Is this a serious question? Check out Ken Ham, Dr Dino & Answers in Genesis- all online. I've seen evidence that not only did they exist, they're not extinct!
However, with all do respect, in answer to the 1000 year old reptiles, Dinosaurs are not reptiles. They are more closely related to birds. Specifically, reptiles have no shoulders or hips. Their appendages grow directly from the spine. It is also thought that dinosaurs were warmblooded, though I can't recall at the moment what the exact reasoning was.